In my little Cessna, in the sim, have flown under Sydney Harbour Bridge a few times. Easy. Now, could I get under the Gateway Bridge, Brisbane (that's the bridge over the Brisbane River you see on approach from the south into runway 01. Could I do it in the Concorde? Probably not, but in sim-world, now that'd be a feat. It is a lovely pair of bridges. https://en.wikipedia.org/wiki/Sir_Leo_Hielscher_Bridges "the bridge owes its distinctive shape to air traffic requirements restricting its height to under 80 metres (260 ft) above sea level (all features of the bridge including light poles) coupled with shipping needs requiring a navigational clearance of 55 metres (180 ft).". I've stood a few times on the bridge, which provides a great view of the airport, river, CBD, and watched flights on descent into 01, one of the best places to be a plane spotter. (I lived in Brisbane for some years.)