171. A City With an Idol

Avodas Kochavim 9:10

One who is traveling is not permitted to pass through a city that has an idol in it if the route goes specifically to that destination. If it goes elsewhere and he just happened upon the city with the idol, it is permitted.

Avodas Kochavim 9:11

It is prohibited to build a dome under which to place an idol, even in partnership with an idolator. If a person violated this law and built such a dome, the wages he earned are permitted. One may build a palace or a courtyard to place that dome, even at the outset.