These caves are off the beaten track from most of the touristy things. Here, you find volcanoes that spew mud. When organic matter underground starts decaying, it emits natural gas and along with the natural gas, mud also spills out. There are limestone caves that allow you to take a peek into the past and try to solve a question or two about natural formations. Dense tropical and Mangrove forests also enable you to enjoy unique flora and fauna species.