Exactly that. For many years there weren't gates that were safe to open. Back-to-back terraced houses could be pro IRA one side, backing on to pro UDA or UVF the other side. Not just gates across roads to separate communities but also walls, fences and barbed wire. Think Jerusalem and you've got the idea. I did a day trip (flew) from the Midlands with a school group to Belfast, once. A real eye opener. Ex IRA guide in the morning, handed over to an ex UDA at the peace line at lunchtime and then Stormont with ex IRA hunger striker, now politician, for the early evening. By coincidence, a relative was previously Chief Executive of Northern Ireland Transport. He only had one bus hijacked during his tenure although the Belfast-Dublin rail line was frequently the target of bomb scares. A fascinating city to visit with very welcoming people. Just chose the moment carefully.....and your guide(s).