Omean

Tons upon tons of dirt must have been removed, and for a long time he wondered where it had been deposited, until in following downward a tunnel of great size and length he sensed before him the thunderous rush of subterranean waters, and presently came to the bank of a great, underground river, tumbling onward, no doubt, the length of a world to the buried sea of Omean.

The Chessmen of Mars 1922

Then I glanced below me, and there I saw a rapidly diminishing circle of light -- the mouth of the opening above the phosphorescent radiance of Omean.

The Gods of Mars 1913

There seemed but one thing to do, and that to choose the easier death which confronted me, and so I moved on down the corridor until the cold waters of Omean closed about me, and I swam on through utter blackness toward -- what?

The Gods of Mars 1913

In perhaps half an hour he returned to report that there was no sign of a patrol boat or of the enemy in any form, and so we moved swiftly and noiselessly forward once more toward Omean.

The Gods of Mars 1913

"A little to your right," cried Xodar, for there are no points of compass upon Omean where every direction is due north.

The Gods of Mars 1913

As we estimated that it would require over a million men to man the thousand great battleships we intended to use on Omean and the transports for the green men as well as the ships that were to convoy the transports, it was no trifling job that Hor Vastus had before him.

The Gods of Mars 1913

We now felt that it would be some time at least before the returning First Born could reach the surface of Omean, and that we would have ample opportunity to make for the subterranean passages which lead to Issus.

The Gods of Mars 1913

As he ceased speaking a weird call rang out across the waters of Omean.

The Gods of Mars 1913

Then through the tunnel and up again to the pool from which we had had our first introduction to the wonderful passageway from Omean to the Temple of Issus.

The Gods of Mars 1913

If favourable, he was to repair immediately to Thark and devote his time to the assembling of a great horde of green warriors whom it was our plan to send in transports directly to the Valley Dor and the Temple of Issus, while the fleet entered Omean and destroyed the vessels of the First Born.

The Gods of Mars 1913