+10% Faith to cities having Volcano or Volcanic Soil tiles. +2 Culture to districts built on or adjacent to Volcanic Soil tiles. Military engineering units can spend a build charges on the Volcanic Soil tiles for “exploration”, having a probability of obtaining Gold, Faith or Culture. There is also the possibility of discovering new resources or Relics. Each Volcanic Soil tile can be explored up to 3 times. Each time a new resource is discovered, Volcanic Soil tiles receive +1 food, Faith and Culture. Each time a Relic is excavated, provides +50% Tourism to Relics in this city.
Must be built on Rainforest or Volcanic Soil.
+2 Tourism
+1 extra per Era that you've advanced past this Wonder's era