UCLH have released lapse video footage of the first stages of construction and have also produced two podcast interviews, one with Kath and Ed Anderton, whose son Lennie had PBT when he was 15.
The second is an interview with Dr Yen-Ch'ing Chang, a paediatric consultant, explaining how PBT works and the development of the facility at UCLH.
Currently, proton beam therapy is unavailable in the UK and can cost upwards of £75,000 in foreign clinics.
The NHS facilities aim to reduce this cost to £40,000 per patient.
Sir Robert Naylor, chief executive of UCLH, told the BBC: "To have work under way on this long-awaited centre is tremendous news.
"This will be a game-changer for NHS patients who will benefit from local access to advanced treatments."
Figures suggest that currently between 120-140 patients a year have to go to foreign clinics for treatment funded by the NHS.
The UCLH facility is due for completion in 2019, while a second NHS facility, the Christie Cancer Centre in Manchester, is scheduled for completion in 2018.
Alongside these two new facilities, in the private sector, Proton Partners International plan a Newport centre that will offer some NHS treatments.