Tent

The Sims: Vacation
Tents are one of the lodging options available on Vacation Island. In the default lots, they will be found in the forest and beach areas.

Tents rent for 79 simoleons a night, and two Sims can sleep in one. When Sims who are sleeping in a tent wake up, they automatically change into the appropriate clothing for the area of Vacation Island they're in. Just having a hotel key doesn't allow Sims to use tents, but Sims that have hotel keys can rent them. While Rental Shack Zack talks of "checking out" when a tent is rented, what appears to happen is that the rental expires at 11:00 AM.

The Sims 2: Bon Voyage
Tents are a type of accommodation in Bon Voyage. Similar to Igloos from The Sims Vacation.

Sims can sleep and WooHoo in a tent. Sleeping in a tent gives the Sim a Vacation Memento.

Sleeping in a tent on vacation is free.