Review for you article
Thames tunnel underwater fancy fair.

Hum. You might want to thoroughly check your information next time - your article was seriously misleading.

There was no fair, let alone fancy. The Brunnel museum only meant that a fair had taken place there a long time ago. So when you mention
Live entertainment
There's a whole host of Victorian themed entertainment on offer during the Thames Tunnel underwater fair. On the first night of the fair a group of local schoolchildren will be recreating a Victorian spectacle and hosting an underwater sideshow for the crowd's entertainment.

Yes, there was a concert the first night. That's it. A whole host of Victorian thamed entertainment on offer? Where?! You do get to see the tunnel... back and forth via the overground. But the only event is to get into the shaft: not that impressive, you need to use all your imagination to picture it as the "grand entrance" it once was.

But:
Get your tickets for the Thames Tunnel underwater fair to travel back in time to the Victorian era. Held at the Brunel Museum, the fair takes its inspiration from the type of fairs that the Brunels held in the Thames Tunnel over 145 years ago.

There is no fair at all. Kids there looked very disappointed. The guide explains how the fair once held (there was only one, I am not sure why you even mention it in plural) so yes, you can say we travel back in time. But "the fair takes its inspiration": there is nothing to see!

I expect apologies for that - makes you wonder how we can trust any information you put on the website after that. a similar experience happenned to me in December for a pop up design bar in Soho... presented as if anyone could go on a Friday night and happened to be only for VIPs.