Tyburn Convent is by Hyde Park, in the centre of London. While the city sleeps, the nuns are already up and in the chapel for their first daily service, Nocturns, at 5.30am.

In an otherwise quiet convent, their voices fill the chapel as they sing psalms together and read from the Bible.

The monastery is built near the spot where, during the Reformation, many Catholics were hung, drawn and quartered on the Tyburn gallows at the top of Oxford Street.

The nuns never leave their cloistered home - unless a trip to the doctors, dentist or bank is called for.

Each nun uses her skills to keep Tyburn running. The day's work is done in silence as much as possible. Mother Lioba says she has a gift for talking, so she shows any visitors around.

The nuns live to a strict timetable, reflected on the busy notice board. Sisters 'in formation' are on their way to becoming fully-professed nuns. Nine of the order's 24 women, who are yet to take final vows, are in London.

Between the seven daily prayer services, plus Mass, the 26 nuns get on with the work of running the convent. That includes washing and repairing many habits.

Once they have taken final vows, they wear a black veil, full length habit, a white cowl while at prayer, a ring and a medal.

"I always pray that there'll be dinner," smiles Sister Catherine, 23, who is single-handedly preparing lunch for 37 people - nuns and guests.

After the Chapel, the refectory is the most important place in the convent for the community, and they process in to lunch as they would into a service.

The nuns pray for people who send in requests - many come by e-mail from their website. The last service of the day, Compline, begins at 8.15pm.