Kind of last minute - looking June/July
Where to go for 2 adults and 17 and 19 year old. Fly into Liberia? Marriott properties or others? Beach, monkeys, sloths, food? Looked through search function but couldn't narrow options down.

Liberia is much easier to maneuver than San Jose. If you fly there, you are not far from Fortuna and Monteverde. Fortuna offers the tours as well as whitewater rafting, bridges, zip lining and good food.

You can also find good beaches such as Conchal, Tamarindo and a few others in that part of the country. Tamarindo is not the greatest beach but definitely a tourist/bar area.

You can also go further south to Jaco/Manuel Antonio/Uvita. It's a little further drive, but my favorite beach is Matapalo (south of Quepos) and it is a close to the tourist area of quepos and Nauyaca water falls/Dominical. Jaco has some good food and nightlife, but crime, drugs and prostitution are plentiful. Avoid the Cocal casino unless you are in the market. It is a great town, and crime is usually petty. If you are aware and don't leave items out, we have never had a problem. Playa hermosa and Bowie point are good places.

All of that is to basically say that you are going during the first portion of the rainy season. Not a problem, but that fortuna and northwest area tends to be a little drier that time of year.

We have never done an all inclusive, so I couldn't tell you much about those.

We will be making our 9th trip there this August to go see some whales in the Uvita area.

I highly recommend flying into Liberia. One of my favorite places in the world is Guanacaste Peninsula. I stay at the Andaz there. It's paradise and only about a half hr from the airport. The beach at Andaz isn't great, but there's an amazing local, secluded beach nearby (playa cabuyal I think) that's almost always empty.

We did a family trip there a couple of years ago. Flew into San Jose, rented a car and drove to the Manual Antonio area. Got a bad ass house with a pool from VRBO near Quepos. Spent 4 days in that area, and then drove up to Arenal. Spent 3 days there.

It was a fantastic trip, but my 2 highlights were Manual Antonio national park, and Tabacon Hot Springs in La Fortuna. At Manual Antonio, we did a private guided nature tour in the Am, and then hung out on the beach in the PM. Tabacon is also a pretty amazing place. Spent almost all day there and nobody wanted to leave.

Did lots of other great stuff, but it was pretty unanimous amongst the family that those were the favorite things.

My neighbor is from Costa Rica and is a travel agent specializing in that area. Let me know if you would like her contact info.