Adobe is a building material of native American origin used to make Pueblos, among other things. It is comprised of mud and straw that has been mixed, shaped into blocks, and left to dry in the sun or a kiln. The straw makes the mud more rigid when it drys, and the mud makes it a hard, mostly waterproof brick when it is dried. Adobe has been used to build many of the structures at Philmont, such as several of the buildings at Abreu Camp. Participants on treks often make adobe as one of the activities at these camps, and even participate in helping to build structures.The blocks are laid side by side like bricks, and then sealed together by splashing water onto the bricks in order to reform the mud and seal the bricks onto the ones surrounding them. The straw is generally trucked in on Philtrucks to the camps or program areas, and the mud is generally dug from the area by participants. The buildings constructed of Adobe are generally cool in the summer and able to maintain heat during the winter due to the nature of the bricks.