the Estado Libre y Soberano de Sinaloa (Free and Sovereign State of Sinaloa) is one of 31 states of the country. It is located on the West Coast, and protected from the Pacific Ocean by the long peninsula Baja California Sur, which forms the Gulf of California. The state is elongated along the cave and much of its surface is coastal plain, with no chance of underground sites. However, there are mountains along the eastern border, unfortunately there are no accessible caves at the moment. The Grutas México (Mexico Caves) are sometimes guided, but this trip is at the edge to a caving trip. It requires a long ride on a bad dirt road, a hike, and numerous crawls inside the cave. Also, we were not able to find contact data for a guide, so speaking Spanish and asking around for guide seems to be the only way to get there.
There are a few caves, for example the 280 m long Grutas del Tesoro (Treasure Caves), but they are only for cavers. The Cueva de los Murciélagos (Cave of the Bats) south of Topolobampo is famous for 5 million bats living inside. Actually there are several Cueva de los Murciélagos in the state but this one is the most popular. Obviously it’s not allowed to enter, but its possible see them leave the cave every evening between April and October.
The state has tourism, though visitors should be careful to avoid the hotspots of the Sinaloa Cartel, one of the most famous organized crime organisations in Mexico. The main sites are beaches.