Redwood Observatory
Redwood Observatory is an adventure map location which removes shroud within a 20 tile radius around the observatory when it's visited. Even areas clouded by a Cover of Darkness will be revealed, though they will be overclouded again at the beginning of the next day. Although Pillar of Fire exists as an underground variant, Redwood Observatory will still work when placed underground.
Additionally, the Observation Tower added in Horn of the Abyss 
is a water variant.
See Also:
