Haephestos (also Hephaestus) is a figure from Greek Mythology. He was the god of fire and blacksmiths.
He plays an important role in Tomb Raider Anniversary, in the level Greece - St. Francis Folly, were he fills out a role previously (in the original Tomb Raider) assigned to Thor. Thor seemed rather out of place in a Greek location so this exchange makes sense.
One of the tasks Lara has to overcome in Haephestos' Riddle is a room with striking thunder. After completing the riddle she enters a room dedicated to Haephestos, which is decorated with murals and a floor mosaic depicting him. The objective in the room is to obtain the Key of Hephaestus by using a big hammer to create two movable statues. These two, and the third one, which already is in the room, are then moved to specific spots on the floor.