ORIGINAL: golden delicious
Consider the absurd situation if you have hexside rivers: Either the town is on one side of the river, and half the time the player can't use the town without sticking his unit on the wrong side of the river,
What's absurd about it? There are any number of historical actions hwere this happened - Borodino for example - the town was on hte "French" side of the River at that battle, and the Russian Jaegers in it had to flee over the bridge.
At Leipzig the entire town was on one side of the river and the French army suffered massive losses trying to flee over the bridges.
At Dresden the town was on both sides of the river.
Arnhem is on both sides of the river IIRC, while hte town of Cassino is only on one side.
or else the designer is forced to place two urban hexes, which is usually excessive.
If a river passes through a town that is small then you can have a minor built up area on both sides even at a major scale - if it is only a hamlet then have nothing - just a bridge.