Every L.A. County Aquarium That Posts Hours, Ranked. Two Are Free. The $49.95 One Is Third.

Four places in Los Angeles County call themselves an aquarium and post hours the public can turn up for. We priced every adult ticket off their own pages on the same day and counted the hours each one keeps in a week. The spread is not subtle: $49.95 at the top, nothing at all at two of the four, and fifty-five hours a week between the longest schedule and the shortest. The most expensive one does not finish first here, and that is not because it is bad.

The criteria, stated once, because a ranking that hides its criteria is a shrug with numbers on it. First, what an adult actually pays at the door, from the institution's own posted price on August 31, 2026. Second, how many hours a week the doors are open, counted off the posted schedule. Third, what each place says is inside, in its own words on its own pages. Parking counts wherever the institution posts a rate, because in this county the lot is part of the ticket. Nobody from this desk went anywhere; every line below came off a screen.

1. Cabrillo Marine Aquarium — free, six days a week, San Pedro

Zero dollars is a verdict here, not a compromise. The City of Los Angeles Department of Recreation and Parks runs this one, and its admission page puts the terms in a single sentence: "Cabrillo Marine Aquarium is FREE to visit year-round, with a suggested donation of $10 for adults and $5 for children and seniors." That is the entire price of the building. It opens Tuesday through Friday from noon to 5 and weekends from 10 to 5 — six days, 34 hours a week, third-most on this page — and beyond the Monday dark day it shuts on exactly four dates: the Fourth of July, Thanksgiving, Christmas Eve and Christmas Day.

Then the part the listings leave out. The building is a Frank Gehry, from 1981, and the Los Angeles Conservancy's entry on it describes chain link used "not as a surrounding fence, but as a set of a three-dimensional objects extending vertically and obliquely from the center of the complex" — mid-career Gehry, reaching for a semi-industrial look that answered San Pedro's fishing and dockworking waterfront. The same entry dates the institution to 1935, when it was a collection of specimens in the Cabrillo Beach Bathhouse, and its own pages still carry the year in the masthead. A listed piece of Los Angeles architecture, open for nothing, six days a week, and most of the county does not know it is down there.

The one cost is the asphalt. Cabrillo Beach parking runs $3 an hour with a $9 daily cap, cards only, per the same admission page — $15 for boats and oversized vehicles, and a $9 flat fee on summer city holidays and special-event days. So a long afternoon is $9, and $0 if you walk or take the bus. Everything else this place does — the lecture series, the volunteer program, the grunion-run programs the Conservancy's entry says made its name — sits behind a door that was never a turnstile.

2. Roundhouse Aquarium — free, seven days, end of the Manhattan Beach Pier

Also free, and blunt about the ask: "The Roundhouse is FREE! However, your donations allow us to operate this wonderful facility," reads the operator's page, which then suggests $5 a person, $10 a family, $20 a group. It is the only aquarium in this county that charges nothing and opens seven days, and until September 13 it is open longer than its standing schedule implies: the extended summer hours it posts for June 12 through September 13 run 9:30 a.m. to 7:30 p.m. on Fridays, Saturdays and Sundays.

The standing April-through-September schedule is 2 to 7 on weekdays and 10 to 7 on weekends, which is 43 hours a week — more than Cabrillo keeps. In October it drops to 29. The nonprofit that runs it, Oceanographic Teaching Stations, counts more than 100 marine animals from Southern California waters in the building, names moon jellies, sharks, octopus, sheephead, moray eels and lobsters among them, and describes a touch tank of sea stars, urchins and snails. The same page dates a $4 million capital project behind the current aquarium and puts annual attendance above 300,000.

It finishes second rather than first for one reason, and the operator says it out loud: the place is small and the schedule bends. Non-public hours go to classes and maintenance, and the posted hours are "subject to change due to weather, pier closures, and private events." Cabrillo is a museum building with a research program attached and four closure days on the calendar. Both are free. One of them is bigger and steadier.

3. Aquarium of the Pacific — $49.95, and here is the argument

Here is the pick we expect mail about. The biggest of the four by any measure finishes third on a page where two of its rivals cost nothing, and no part of that is a claim about scale. On scale it wins and it is not close: its own exhibits page claims "more than 100 exhibits, including 19 major habitats," among them Shark Lagoon, the Lorikeet Forest aviary, a colony of Magellanic penguins, the Pacific Visions wing and NOAA's Science on a Sphere. It opens 9 to 6 every day but Christmas, with extended hours on select dates it publishes on a calendar — a 63-hour baseline week, nearly eight times what Santa Monica manages. Nothing else in the county is in the weight class.

The problem is the number on the door. General admission, as posted on the aquarium's own prices and hours page: $49.95 for an adult, $34.95 for a child 3 to 11, $46.95 for a senior 62 and over. Parking is $8 for the day with aquarium validation. One adult, one visit, one car is $57.95, and every upgrade the same page sells — the VIP package, the whale watch, the harbor tour, the HoloTheater — starts from there and climbs. Two adults and two children come to $169.80 before the car is parked.

So the verdict is not that this is the worse aquarium. It is that $57.95 is a real household decision in this county, and the two entries above it are not consolation prizes: one is a Gehry housing a collection its keepers date to 1935, one is a room at the end of a pier, and both keep local species in local water and let you leave having spent nothing. The Aquarium of the Pacific is the right answer once a year. Cabrillo is the right answer on a Tuesday in February, and again in March, and it will still be free in April.

One note for anyone doing the arithmetic anyway: the aquarium's own site says it is running coupons at participating independent grocery stores through September 29. It does not say what the coupon takes off, and we are not going to invent a number.

4. Heal the Bay Aquarium — $12, and eight hours a week

The cheapest ticketed aquarium in the county, and the hardest one to reach in time. Under the Santa Monica Pier the posted admission is $12 for adults and teens 13 and up, $5 for children 4 to 12, $10 for students and for adults 65 and over, $6 for EBT cardholders, and free for active-duty military, retired military and veterans. Groups of ten or more children go in at $3 a head. On price and on who gets a break, this is the best-designed door on the page.

Then the hours: "General Hours: Saturday & Sunday 12 PM – 4 PM." Eight hours a week, both of them on a weekend, and the same page already lists four more closures booked for September 19, 20, 26 and 27. There is no weekday option and no after-work option. Miss your Saturday and the next window is seven days out.

It ranks fourth on the schedule and on nothing else. The nonprofit puts over 100 local species in the building, and its own exhibit list is specific in the way that only people who collected the animals themselves get to be: swell shark egg cases in the nursery, moray eels on the rocky reef, halibut lying flat in the sand in an exhibit called Under the Pier. For a room beneath a boardwalk, assembled out of the same bay Heal the Bay grades in its Beach Report Card, that is a serious collection kept behind a very short door.

Go by train. The pier's own directions page prices the Metro ride from 7th Street/Metro Center in downtown at $1.75 with two hours of free transfers, calls it about 46 minutes, and puts the walk down from the Downtown Santa Monica station at ten more. Nobody on that page volunteers what the parking costs.

Not ranked, and why

Three other names come up when you go looking, and none of them belongs on the list, for three different reasons.

A fourth name comes up in searches: the Newhall Aquarium, in Santa Clarita. Its own website, when we checked, was four "Coming Soon" panels over a 2025 copyright line, with no address, no hours and no admission policy anywhere on it. A ranking built on posted hours cannot rank a place that posts none. Publish a schedule and it goes on the page.

The SEA Lab in Redondo Beach is the one people still ask after. It closed at the end of June 2019: NBC Los Angeles reported that the LA Conservation Corps ended the program after a real estate investor acquired the property, and that animals not ready for release were sent to other aquariums and rehabilitation centers. Twenty-two years of touch tanks, ended by a lease.

And the Marine Mammal Care Center is not an aquarium at all — it is a hospital for sick sea lions and seals — but it is in San Pedro, it is free, it opens Friday through Monday from 10 to 4, and it asks visitors to reserve online because walk-ins are limited. If you are already down there for Cabrillo, that is the rest of the afternoon.

One last piece of arithmetic, because the four schedules are more interesting added up than read one at a time. Los Angeles County offers 148 hours of aquarium in a normal week — 155 until the Roundhouse's extended summer hours end on September 13. Seventy-seven of those hours cost nothing, or 84 inside that window. The most expensive ticket in the county buys 63 of them, and the whole argument on this page is whether $49.95 is the price of an aquarium or the price of the biggest one.