Perhaps the following is well known, anyhow I stumbled upon what I think is a (minor) bug. As far as I know, caravans can establish trade routes within own civilization if: 1) the distance between the home and target city is 10 or more squares -OR- 2) home and target city are on different continents Somehow, when the target city is building a wonder, the second rule is inhibited. Save attached. There is a caravan from Chapultepec. Try to move it to Tlaxcala, which is on different continent and building a wonder (Mich.'s Chapel). It is impossible to establish a trade route. Change the production at Tlaxcala to, say, Cathedral - establishing a trade route is possible. Try the same with Tecamac (building wonder, on different continent, but more than 10 squares distance from Chapultepec) - it is perfectly possible to establish trade route.