Located on the inside of and on top of the parahippocampal winding in the floor of the temporal part of the lateral ventricle. The hippocampus is at the front quite large and wide, resembles an animal paw (pes hippocampi), tapers backwards and turns into it initially flat, then spaghetti-like bundle of nerve fibers called the vault (fornix). The hippocampus area includes four subdivisions:

1) the small grey-brown cobbled toothed winding (Gyrus dentatus),

2) the hippocampus proper or the horn of Ammon (Cornu Ammonis, CA region);

3) the hippocampal support (subiculum) and

4) The arch fringe/arch band (Fimbria/tenia fornicis) or as it is also called the hippocampus fringe/band (Fimbria/tenia hippocampi) which is the very beginning of the fornix and passes into it at the same time as the rest of the hippocampus more or less ceases.

The hippocampus is absolutely crucial for our learning ability when it comes to being able to recall facts (names, events, faces, etc.) of various kinds (explicit or declarative memory).

The hippocampus enables us to orient ourselves spatially, especially when it comes to going back and forth in a previously unknown area, e.g. getting out for a walk from the hotel in a city that we are visiting for the first time and then being able to find our way back without much trouble.
When it comes to well-rehearsed spatial perceptions, e.g. to orient yourself in the home you have occupied for years, to find your way to and from the grocery store in the area where you have lived for several years, to know at which stop to get on / off to get to your old usual workplace, etc., well, then the striated nuclear system (striatum) seems to be of greater importance than the hippocampus.

Amnesia.