Here is a fully-functioning caravan built entirely using 215,158 LEGO pieces. It took over 12 weeks and more than 1000 hours to build this beauty. This model measures 2.2m tall by 3.6m long. It has a sink with running water, lights, a bed, a chess set, and everything one would need to spend some time inside.
The above video gives you a quick look at what this LEGO Caravan has to offer. You can catch it at BRICK 2015.