Have you ever looked into the mouth of an active volcano?
If you are not afraid of looking directly into the vibrant heart of mother nature then Masaya Volcano is for you: Bubbling lava, sulfur gas and basalt stones. The transport will take you directly to the top of the volcano. For safety reasons you will only be allowed to spend 15 minutes looking into the beast.
The volcano is not always active so enjoy it while it lasts!