Kurma prishth bhoomi: high in the centre and sloping in all four directions like a tortoise's back. It brings riddhi-siddhi, prosperity, happiness and business growth, and gives a temple great attraction.
Gaj prishth bhoomi (as taught here): slopes toward both the North-East and the South-East. It is not good; correct it by raising the South-East a little and keeping the whole slope toward the North-East.
Daitya prishth bhoomi: slopes toward the South-West and North-West, with the North included. Even with a fall to the North, a slope at the zone of Rahu-Ketu raises demon-like troubles, as the name says.
Naag prishth bhoomi: slopes toward the West, East and South. Work runs well at first, then one massive loss takes away all the money. Share traders in particular must avoid it and keep their slope toward the North-East.