Kent coastline of Kent is continuously changing, due to tectonic uplift and coastal erosion. Until about 960, the Isle of Thanet was an island, separated by the Wantsum channel, formed around a deposit of chalk; over time, the channels silted up with alluvium. Similarly Romney Marsh and Dungeness have been formed by accumulation of alluvium. Kent's principal river, the River Medway, rises near East Grinstead in Sussex and flows eastwards to Maidstone. Here it turns north and breaks through the North Downs at Rochester, then joins the estuary of the River Thames as its final tributary near Sheerness. The Medway is
Maidstone, Vermont the southwest, Ferdinand to the northwest, and Brunswick to the north, all in Vermont. Across the Connecticut River are the New Hampshire towns of Stratford to the northeast and Northumberland to the east. The only crossing of the Connecticut River from Maidstone is the Janice Peaslee Bridge in the northern part of town, leading to Stratford village. Vermont Route 102 travels the length of the east side of town, staying in the Connecticut River valley. According to the United States Census Bureau, the town has a total area of , of which is land and , or 5.39%, is water.