Train Hideout Sightseeing Tour AC: Syndicate
The Train Hideout, which unlocks after sequence 3 acts as a mobile headquarter. You can collect your earnings there, access souvenirs and gang upgrades, all while on the road which gives you the opportunity to hop out whenever you want.
Near the front, you can also find the sightseeing feature at a highlighted door. You can choose from several different exterior angles with the D-Pad and take a look at London.