Staff and students require their ID cards to enter the Tottenham Centre - the main building - through one of five turnstiles, which were installed more than eight years ago. A uniformed security guard sits between them, while another surveys things from a window a few metres away.
Like all institutions, the College of North East London is keen for as many learners as possible to come through its doors. Having just spent pound;19 million on a refurbishment programme, it is anxious toprotect what it has from those who may see a college as an easy target for crime.
Mike Paskin, head of estates, knows that the college is in one of the country's most deprived areas. While violence and other crime is rare, there is always a possibility that the college will be a target, as it was 18 months ago when thieves stole 48 personal computers.
Two sites have been sold, leaving two more, both on Tottenham's High Road. "We have spent a lot of money on estates and improved efficiency, but that means we have moreconcentrated use of buildings with more bodies in a very busy environment," says Mr Paskin.
With about 12,000 students and 700 staff, the college already opens six days a week, and may extend that to seven in the future. Mr Paskin adds:
"We are under pressure to get more people in. It is difficult to keep a place secure when it's hardly ever closed."
The college employs Independent Consultant Services, which provides four security guards who are on duty whenever the college is open to the public. They are supported by a team of 12 caretakers, who also perform maintenance and other duties.
Its buildings are in an area that police say has the highest level of crck-cocaine use in Britain. Although there is no evidence that students are taking drugs on college premises, the drugs trade tends to encourage petty crime. Computers, particularly their micro-chips, are potential rich pickings for addicts desperately trying to fund their habit.
The college spends about pound;200,000 a year on security, of which about one-third is paid to ICS. Later this year, the college is due to invest pound;95,000 in a new digital CCTV system, which will provide better quality pictures and more convenient ways of checking earlier recordings.
Although security is expensive, Mr Paskin believes that the college has no option but to spend these sort of sums so that learning takes place in a safe environment. "If people come into the place and feel it's safe, they are going to choose this college rather than go somewhere else."
Students without ID cards can be issued with a one-day pass, but security guards and caretakers look out for known trouble-makers who may be turned away if they turn up - with or without a pass.
"We try to avoid confrontation," says facilities manager Reg Brooks, who is responsible for managing the team of in-house caretakers. "We keep a low profile but have procedures in place should something get out of hand."
During the next 12 months, it is likely that outside security guards will be phased out and caretakers given a wider security role. By way of preparation, caretakers have attended a two-day course in personal safety and conflict management, which included guidance on how to handle provocation and how best to protect themselves and others against violence.
In part, the switch to an in-house security team is informed by a desire to be seen as less confrontational, while still ensuring safety.
However, Mr Paskin is aware that the college is a public facility. "We are under pressure to let in anybody who has a legitimatereason to be here," he says. "It'sdifficult to preclude people who use education as a pretext forgetting in for other activities."