Porchester Spa is the capital’s oldest spa and has been offering detox for generations of people since its inception in the late 1920s.

Nestled behind the doors of a Victorian building in busy northwest London, this is like no other spa I have experienced. Which seems silly considering its origins.

The spa underwent a refurb in 2003 but many of its original features remain intact.

As soon as you walk through the doors, you feel like you are being transported into a different time in space.

Opulence is the key word here – stone floors and walls, grand pillars, high ceilings and a sweeping marble staircase. I notice on the way in that mobile phones are banned so they are clearly serious about creating an oasis of calm.

And that is exactly why I’m here. The spa’s management team has set me a challenge – to spend an evening at the Porchester and not come away feeling anything but utterly calm.

I have a busy job with long hours behind a desk so they didn’t have to ask me twice.

The Porchester is vast, boasting two relaxation Russian stream rooms, three Turkish hot rooms and a Finnish sauna cabin. For the brave, there is also an ice-cold plunge pool.

I visited on a Friday evening which is for women-only (there are also men’s and couple’s evenings). At ground level there are dozens of recliners for visitors to relax with a book or a magazine, or catch up with friends. There are also tables and chairs for people to enjoy a snack served from the kitchen.

There are also a wide range of affordable exfoliation and massage treatments including a hot stone massage, body coffee exfoliation and an Indian head massage. For men, there are traditional wet shaves. Beauty treatments are also available including manicures, tanning, waxing and facials.

My evening kicks off with a much-needed massage. I’m taken to a private room and my masseuse gets to work – it takes 30 seconds for her to realise my shoulders are a knotty mess. Initially, it’s a bit painful – but in a good way. She tells me later that she had to get through several layers of muscle to actually reach the knots – closer to the bone than skin. The fact that she managed this with very little discomfort and that I still felt relaxed and floated out of the room is a testament to her skills.

After the massage is over, I spend some time in the sauna and one of the steam rooms. It’s no exaggeration that this is far from your average steam room. Intense but not overbearing, my skin felt and looked clean and my sinuses were clear. How did the challenge work out for me? I felt invigorated yet calm and it was the perfect end to the week. Devoting time to yourself really is beneficial for body and mind.

Porchester Spa is open daily between 10am and 10pm. Ladies’ days are on Tuesday, Thursday, Friday and Sunday (until 4pm). Men’s days are Monday, Wednesday and Saturday. Couples’ time is Sunday between 4pm and 10pm. For more information call 020-7792 3980 or visit www.courtneys.co.uk/centres/Porchester/the-porchester-spa.