Hippocampus (mythology) Poseidon (or Roman Neptune) often drives a sea-chariot drawn by hippocampi. Thus hippocampi sport with this god in both ancient depictions and much more modern ones, such as in the waters of the 18th-century Trevi Fountain in Rome surveyed by Neptune from his niche above. The appearance of hippocampi in both freshwater and saltwater is counter-intuitive to a modern audience, though not to an ancient one. The Greek picture of the natural hydrological cycle did not take into account the condensation of atmospheric water as rain to replenish the water table, but imagined the waters of the sea oozing back
Neptune Neptune Neptune is the eighth and farthest known planet from the Sun in the Solar System. In the Solar System, it is the fourth-largest planet by diameter, the third-most-massive planet, and the densest giant planet. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times the mass of Earth and slightly larger than Neptune. Neptune orbits the Sun once every 164.8 years at an average distance of . It is named after the Roman god of the sea and has the astronomical symbol ♆, a stylised version of the