This is St. George's Church in Madaba. The mosaic on the floor of this church is the most famous and important one as cultural heritage in Madaba.
The one railed-off with red coloured chain is the floor mosaic, a bird's-eye view of Palestine area. The dark part with a boat in the center is the Deadsea, the river flows from the left side is the Jordan river. Big river flows into the Deadsea is only one which comes from the north. But the town of Madaba where this mosaic is on the eastern side of the Deadsea. It means this mosaic's bird's-eye view was drawn from the opposite, far western side of the Deadsea. It was difficult to understand this map for the people of that time, maybe.