In a normal street your neighbours are beside you and your upper floors are out of reach. Here they are below you, and their roof, terrace or parapet is very often at the level of your first floor. That turns an upstairs window or a balcony door — the openings almost nobody bothers to lock — into something genuinely reachable, without a ladder and without anything that looks like climbing.
It is the most useful thing to understand about property here, and it is rarely on anyone's list. A household will have a solid front door, a serious gate and a first-floor slider that has never once been locked because it is upstairs. On this slope, upstairs is not the protection it is elsewhere, and dealing with those openings is straightforward lock installation work.
The second condition is the railway. It runs along the shoreline between the houses and the water, a narrow, continuous, entirely unwatched corridor with no lighting and nobody on it after the last train. Properties on the seaward tiers have a boundary onto that rather than onto a beach or another garden, and it deserves the treatment a rear service lane would get in an inner suburb.