Watch John Ryall's report below
This weekend marks the 25th anniversary of the inauguration of the Eurotunnel.
To celebrate, Graham Fagg, the construction worker who was there at the moment of the Channel Tunnel breakthrough, was invited back to recall that day.
Graham from Kent had been the construction worker to first drill through the chalk in May 1994 and shake hands with a French engineer on the other side.
There are now some 400 trains every day using the Channel Tunnel.
This equates to around 12,000 cars, 7,000 trucks and 60,000 people, going through the tunnel on the Eurostar.
During the last 25 years, the Channel Tunnel has seen fires, financial crises, huge success, and is facing now the challenges of Brexit.
We're 25 years into a 99-year concession. So we're going to be here until 2086, so we've still got plenty of scope to grow here. And if we outgrow it, we already know how to build this one, so we'll keep going."