Heat lightning can also occur if cloud-to-ground lightning occurs very far away and the sound dissipates before it reaches the observer. At night, it is possible to see the flashes of lightning from very far distances, up to 100 miles, but the sound does not carry that far.
Fungal Grotto is a 4-man dungeon in Elder Scrolls Online. It is located all the way at the western edge of Stonefalls.
Blue Grotto is actually a sinkhole with good visibility. Depths reach 100 ft. Upon entering the sink you will encounter a very large cavern with writing on the walls. At a depth of 30 feet there is a fresh air bell so you can take off your mask and breath some fresh air. Continuing down, there is a large shaft that slopes down at a 90 degree angle. At around 90 feet you will encounter silt that can be easily stirred up. There are lights at 30 ft to illuminate the cavern. The owner, is very friendly and also manufactures dive, wreck and video lights.