The Java Lava Coffee House is an internet café/coffeehouse owned and run by the Finster family in the last two seasons of Rugrats and the entirety of All Grown Up! Chas and Kira purchased the building in the Rugrats episode "Sweet Dreams".
In All Grown Up!, Chuckie and Kimi work there part-time, while Betty helps Chas and Kira run the place.
As babies, the Rugrats used to play in the playpen there sometimes. When they have grown up to be teenagers, they (including Angelica and Susie) would stop there to hang out after school. The coffee house is also shown to be a very popular hang out location for other kids too.