This tube map shows the average property prices at every London Underground station

Click for the full-sized map

Everyone knows that if you ever want to get on the property ladder in London, you're going to need a helluva lot of cash. To quantify just how money we're talking about, the folks at TotallyMoney.com have put together this handy (if depressing) map, which shows the average house price, per square foot, within 0.3 miles of every London tube station. To put it into context, the average one-bedroom flat in London is about 500 square feet, so you don't need to be a mathematician to work out that Zone 1 is pretty much off-limits unless you're secretly sitting on a pile of gold.

The research shows that the Hammersmith and City line is the most expensive at £1,125 per square foot, while the Metropolitan line has the cheapest average property price, at £504 per square foot. Although, it's worth bearing in mind that the Metropolitan line stretches all the way out to Zone 9, so you might save on property but you'll have a seriously long (and expensive) commute.

Want more depressing property maps? This one show how unaffordable renting in London is.

Here are 25 things you didn't know about the tube.