Tim Dunn explores disused tube station Down Street in Mayfair that played a crucial tactical role during WWII and tours Rotterdam's new centraal station with the man who designed it.

Tim Dunn visits the Ffestiniog in Wales originally built to transport slate from mountain to coast and learns about Amsterdam Centraal - controversially built across the waterfront.

Tim's behind the scenes at London's King's Cross and learns of Bristol's funicular railway.

Tim Dunn visits the Ribblehead Viaduct in the Yorkshire Dales, talks to the man who saved it from closure and tours the breathtaking stations of the Hungerbergbahn in Innsbruck.

Tim Dunn follows his family's roots by exploring Metroland, the area around the Metropolitan Railway, and in Great Malvern learns about the woman behind the decorative 1860s station.

Tim Dunn explores the ornate St Pancras station in London and its sister hotel - built to show off the might of the Midlands, and learns about Castle Howard station in North Yorkshire.

Tim Dunn rides up Mt Snowdon's railway to visit the summit station, and discovers how a glass structure envelopes Strasbourg's 19th century station.

Tim Dunn visits the former HQ of London Underground, 55 Broadway, which was the capital's first skyscraper, and sees the timber-framed Barmouth Bridge in north Wales.

Tim Dunn visits the architecture of the Stockton & Darlington railway, the first passenger steam line in the world and learns how Essex's enormous Chappel Viaduct was built.

Tim Dunn visits Swindon's railway village, which became home to Great Western's enormous works and he also explores the dark and secret past of Milan's monumental station.