Most of what goes wrong at Manuel Antonio happens before anyone reaches the trail. Guests arrive at the gate expecting to buy a ticket, arrive on a Tuesday, or turn up with a plastic water bottle and a bag of chips and get sent back to the car. None of that is obvious from the outside, and none of it is well signposted in English.

This is the practical half of the park — what you have to arrange in advance and what the rangers will actually stop you for. If you want the beaches, the sloths and where to stay, that is in our Manuel Antonio guide.

There is no ticket booth. Every visitor buys in advance through SINAC's official portal at serviciosenlinea.sinac.go.cr — you create an account, verify the email, then pick a date and a 15-minute arrival slot. It is the only legitimate channel; the sites that appear above it in Google search results are resellers.

The park admits 600 people a day and that number is enforced. Between December and April, plan on tickets going three to four weeks out. In green season, May to November, one to two weeks is usually enough. If your dates are fixed, buy the ticket before you book anything else in Quepos.

Bring the physical passport or ID whose number you entered at purchase. Rangers check the name against the ticket, and a photo of the passport on your phone is not accepted.

The park runs Wednesday to Monday, 7:00 AM to 4:00 PM. It is closed every Tuesday for trail maintenance and to give the wildlife a day without 600 people in it. That closure is the single most common trip-planning mistake we see — people build a two-night Manuel Antonio stop where the only full day lands on a Tuesday.

Admission is booked in 15-minute slots running from 7:00 AM to 3:00 PM, so you choose your arrival time to the quarter hour when you buy the ticket. Take the earliest slot you can stand. It is not about crowds so much as animals: the monkeys and sloths are active in the cool hours, and by eleven the canopy goes quiet and the heat on the exposed stretches becomes real work.

Hours and fees are set by SINAC and do change — the park's official page is here if you want to confirm before you travel.

Manuel Antonio enforces a strict single-use-plastic and outside-food policy, and bags are checked at the entrance. What gets turned away: disposable water bottles, plastic bags, and commercially packaged snacks — chips, cookies, anything in a wrapper.

What is fine: water or drinks in a reusable bottle or flask, and cut fruit in a reusable container. Bring the reusable bottle; there are refill points inside.

The rule exists because of the animals, not the litter. The capuchins and raccoons here have long since worked out that bags contain food, and a fed monkey becomes an aggressive monkey with a shortened life. Do not feed anything, and do not leave a daypack unattended on the beach — the capuchins open zips.

Closed-toe sneakers or light hiking shoes for the boardwalks and trails, with sandals in the bag for the beach. Light, quick-drying clothes; wear your swimsuit underneath rather than trying to change in the park. Then biodegradable sunscreen, insect repellent, a quick-dry towel and dry clothes for the drive back.

Sendero El Perezoso (the Sloth Trail) is a flat wooden boardwalk and the highest-probability sloth spotting in the park — go slowly and look for a lump that does not match the branch.

Playa Manuel Antonio is the sheltered bay: calm, warm and the reason to carry a towel. Playa Espadilla Sur is wider and generally emptier if you want a walk rather than a swim.

Sendero Punta Catedral is a moderate loop over the headland with Pacific overlooks. Worth knowing: Punta Catedral used to be an island, and joined the mainland as sand accumulated behind it — a tombolo, and the reason the park's shape looks the way it does on a map.

Honestly: for wildlife, yes. The difference is a spotting scope and someone who knows which tree the sloth was in yesterday. Unguided visitors walk past most of what they came to see — the animals here are small, still, and extremely well camouflaged.

Guides are certified by the ICT and you will be offered one at the entrance. If you would rather have the guide, the transport and the ticket handled as one thing, that is what our guided Manuel Antonio park walk is; it ends on the beach with time to swim. Getting here from the airport is a two-and-a-half to three hour private transfer.