FOUR SEASONS SULTANAHMET
Birds chirp as they fly free over the herb garden in the gloriously tranquil central courtyard. They have got considerably more freedom to roam than the original inhabitants, however. This peaceful retreat, lined with orange and lemon trees and graciously hosting the restaurant's terrace tables, was once the exercise yard. Further touches still remain among the perfectly-located luxury - the lifts go up the former watchtowers and the old wooden doors are still in place - and surprisingly little has had to be altered in the lobby and bar in order to add class to the clink chic.
Deluxe rooms from $429 a night. See fourseasons.com/istanbul.
The niches in the walls of the former solitary confinement cell of this ex-military prison flit between religions. One has a Hindu altar, the next a Christian one, the next Jewish. The other cells have all been individually converted by a different artist. The "English cell" - No.119 - has miniature Antony Gormley figures protected in a glass case. In short, the Celica is simultaneously one of the world's greatest hostels and a giant art project. And one entirely fitting with Metelkova - the bar- and studio-packed quasi-autonomous semi-squat that surrounds it.
Dorm beds from $27, private rooms from $63. See hostelcelica.com.
THE LIBERTY HOTEL
The former drunk tank of the Charles Street Jail is now Alibi, Boston's most happening cocktail bar. And the snug red brick alcoves of Clink modern American restaurant were previously cells. But it's the staggering octagonal main building - now the lobby, with guest rooms stacked high above it - that elicits wows from virtually everyone who sets foot inside. The jailhouse look of the rooms here is most apparent, but the bar and DJ noise means they're only for people who really want to join the party. The wings host toned-down rooms and suites, many with fabulous river and city views.
Deluxe rooms from $414. See libertyhotel.com.
The velvety vampire-lair goth flamboyance of the lobby gives way to the soaring magnificence of the main atrium. Natural light floods in, while floor after floor of cells stack up to the arched roof. Her Majesty's Prison Oxford was closed in 1996, deemed unfit for inhabitation. But after a glam refurb - three cells have been knocked through to make one room, metal bars over the tiny windows have been replaced by wood - its new incarnation is an affordable luxury Malmaison has people begging to be locked up. Authenticity remains in the heavy, studded, original cell doors.
Cell doubles from $243 a night. See malmaison.com/locations/oxford.
The former Langholmen jail - which closed down in 1975 - has a location worth committing a few crimes for. On a leafy island in Stockholm's labyrinth of waterways, it has been turned into a part-hostel, part-Scandi-spartan hotel. Old barred windows have been left in place, ladders that joined bunks have been cleverly worked into the decor and chunky iron strips secure the doors. There's even a small museum for guests wanting to dig further into prison life. The cosy on-site pub, however, is a privilege for guests not afforded to the original occupants.
Dorm beds from $41, doubles from $142. See langholmen.com.
BEST WESTERN HOTEL KATAJANOKKA
The high red brick perimeter wall is the first clue, the classic four wings in a cross shape is the second. For 165 years, more than 40 per cent of Finland's prisoners passed through this pre-trial facility. They got a seven-square-metre space with no toilet or shower. Now, the smartly stylish queen rooms - three cells knocked together with bathrooms mercifully installed - bear little trace of the past, aside from the old photos above the headboard. The atmospherics are best retained in the Jailbird restaurant and vaulted wine cellar.
Queen rooms from $180 a night. See bwkatajanokka.fi.