Slope

http://houseconstructionindia.blogspot.in/2009/10/vaastu-shastra-slope-of-site.html
From the appearance of the surface land is divided into following four categories:

1. Elephant's back: The land which is somewhat elevated in the south, south-west, west or north-west directions is known as elephant's back. Goddess of wealth, Lakshmi is said to inhabit such land. The occupants, naturally, grow rich and enjoy long life on such a land.

2. Turtle's back: The land, which is elevated in the middle and shallow all around, is known as Turtle's back. Inhabitation on such land leads to greater enthusiasm, luxuries and accumulation of wealth for the occupants.

3. Demon's back: The land which is elevated in north-east, east and south-west directions is known as Demon's back. Inhabitation on such a land leads to loss of wealth and children.

4. Serpent's back: The land, which is elongated in east-west directions and elevated in north and south directions is known as Serpent's back. Inhabitants on such land meet untimely death. They also lose their wives, sons etc. and have lot of enemies.