The longest climbs of Central London can be found to the east of Hampstead Heath in the slopes up to Highgate.
Swain’s Lane is the most famous and most difficult way to the top, with some parallel roads available to mix it up a bit.
Swains Lane starts from the roundabout on Highgate Road north of Kentish Town. A flat traverse ends with a left hand bend up onto the climb. The hill has three distinct sections, starting with 500m at 6-7% where you can carry some speed from the flat, before the road ramps up into a one-way section flanked by brick walls for 200m at 12-15% and then a final false-flat style finish for 200m at 5%.
Hillway is a private road that runs in a straight line through what must be some of the most expensive real estate in London. Slightly shorter than the full Swain’s climb, it makes up for it with an unrelenting 10% gradient. Hillway is ideal for a hill repeats session, as you can go up and straight back down as opposed to Swain’s which sits on a one way system with a slightly protracted loop back to the base. The views over the lights of London from the top down to half way back to the bottom are always excellent at night.
Highgate Hill West heads to the same summit as Swains, but is slightly longer and less intense gradient wise. The main issue with this road is the traffic, with several bus stops on the way up that can lead to KOM-hampering stoppages.
Highgate Hill rises up from Archway to the top of Highgate. Another where both traffic and traffic lights can cause hold ups and not one you’ll want to go up and down regularly but with a gentler gradient than Swain’s it can work to mix it up with a ride up Highgate Hill if doing reps.
Turns out there’s one more way up, only discovered it this year. Millfield Lane runs up the side of Hampstead Heath, after turning off Highgate West Hill near the bottom. The climb starts gentle, and builds up and up through a private road, before a right turn and a pretty vertical final couple of hundred metres to the top. Good one to mix it up.