This is the lip of the Masaya Volcano. In our own litiginous society I highly doubt we would be allowed this close. In the park's instructions it says: "In case of expulsions of rocks you should protect yourself under the car."
Note the vultures flying over. Actually, the volcano is more populated by a flock of parrots that are immune to the sulfuric gases and have nests burrowed into the volcanic rock.