As we made our way from Waterloo station towards the South Bank, my seven-year-old son Reuben pointed to a huge circular glass building situated in the centre of a busy central London roundabout.
'What's that?' he asked, intrigued.
The landmark that had caught his attention was the striking BFI IMAX, which is notable for its unique design and for housing the largest cinema screen in the UK - 26 metres wide and 20 metres high.
It opened in 1999 but in recent years it was renovated, and it is a must-visit destination for film buffs.
But in the many years I've lived in London, and despite all the times the iconic building caught my attention, I'd never got round to visiting.
So, with the family-friendly superhero movie The Fantastic Four: First Steps showing, it felt like the perfect time to finally explore this one of a kind cinema with Reuben and his 10-year-old brother Odhran.
Entering the venue offered excitement in itself for the kids, as you have to access through an underpass.
Unlike other cinemas, there is only one huge screen at BFI IMAX, with capacity of just under 500.
Stepping into the foyer, we made our way up the stairs to grab our snacks. Expect the usual treats of nachos, hot dogs, pick 'n' mix, popcorn and ice-cream. For an idea of pricing, a sharing combo of one large popcorn, one bag of sweets, and two large drinks, will cost you £17.99. If you fancy an alcoholic drink, there's a selection of Prosecco, wine, spirits, ciders and beer on offer. There's also a lovely bar area downstairs, where you can sip on a cocktail.
As we entered the cinema, the size of the screen was impressive. The front row of seats are set several feet high and far enough back to allow for comfortable viewing. We were located in row N, towards the back of the cinema. We visited on a Sunday afternoon and it was busy.
It was incredible to think that just 13 feet below BFI IMAX, the London Underground line is running. But the venue has been sound-proofed and has anti-vibration bearings, so you would never guess there were trains travelling underneath.
So, aside from being the largest cinema screen in the UK, what else makes BFI IMAX so special? Film-fans will be interested to know that it is one of only two screens in Europe that can show films in both IMAX 70mm film and digital formats. This means it can project both traditional film reels and modern digital content, allowing for a wider range of film screenings. Tickets are now available to experience the first IMAX 70mm screening of Christopher Nolan's The Odyssey next summer.
If you're not a film-buff and are wondering what 70mm means, well it refers to the projection of the movie on to the screen. It's a wider format that allows for a higher-resolution image, resulting in a more detailed and vivid picture.
Another thing that sets BFI IMAX apart, is that it features Laser projection for sharper, brighter images, and it's equipped with a 12-channel digital surround sound system, for a powerful audio experience.
In summary, we found it the perfect cinema to catch an action-packed movie such as The Fantastic Four: First Steps. It was a completely immersive experience, that really allowed us to feel part of the world we were watching.
Another great thing about BFI IMAX is that it doesn't just show the big blockbusters. It also shows alternative content and hosts educational presentations. And it celebrates anniversary screenings, such as this month's screenings to celebrate the 50th anniversary of Jaws.
Whether you're a film buff, a tourist looking to tick another London landmark off the bucket list, or, like me, a mum in search of another unique experience with the kids, then BFI IMAX is an attraction that needs to be on your radar.
Location: 1 Charlie Chaplin Walk, South Bank, London, SE1 8XR
Cost: Prices for non-members - adults from £16, children (14 and under) from £8, families (one adult and one child) from £19. There's a £1 booking fee per ticket. Prices will depend on your tier of seating, which includes Premium, VIP, and Standard.