Are there any airports with approaches and/or departures that require pilots to fly under an obstruction at some point (thus meaning that, for at least a short segment of the approach or departure, there is not only a minimum safe altitude, but also a maximum safe altitude)?
I can imagine a few situations where this might occur, such as for an airport at the bottom of a deep, steep-sided valley with powerlines or a bridge across the top of the valley, but I don't know if any airports like this actually exist.