Trelew (pronounced Tre-leh-ew) is a commercial, industrial, and service hub that contains the region's main airport. Its biggest attractions are its paleontology museum (with the largest dinosaur fossils in the world on exhibit) and its proximity to the Punta Tombo reserve (though both can also be reached on day trips from Gaiman and Puerto Madryn). Otherwise, the city has little to recommend it: its mediocre hotels are notoriously overpriced, and aside from rental-car firms its tourism infrastructure is far less organized than Puerto Madryn's. If you come in the second half of October you can watch part of the Eisteddfod, a Welsh literary and music festival first held in Patagonia in 1875.
Trelew was founded in 1886 as a result of the construction of the now-defunct Chubut railway line, which connected the Chubut River valley with the Atlantic coast. The town is named after its Welsh founder, Lewis Jones (Tre means "town" in Welsh, and Lew stands for Lewis), who fought to establish this railroad.