Translation:Is there a police box nearby?
"Your best resource for contacting the police, getting directions if you are lost, or for reporting a lost or stolen item, is your nearest “Koban”, or police box. This network of mini police stations is unique to Japan, and they can be found in virtually every neighborhood throughout the country, there are over 1200 Koban in Tokyo alone. While not all Koban are staffed 24 hours a day, most of the police boxes located in heavily populated areas will have an officer on duty."
To illustrate, here's a picture of one:
This is one of those things where it probably takes a lot of study and immersion in Japanese before you get a natural feel for which is right in a particular situation, and how using one or the other subtly changes the sense of what you're saying
Anyhoo, は is more for establishing the topic or setting a new context. So it's like "police boxes - are there any nearby?". Whereas が is more like talking about a specific thing, where you might use it or the in English. "Is the police box nearby?"
I mean obviously I'm still trying to get the hang of it myself, but it feels more natural to me to use は here
Well I mean the only one who ever uses them here these days is this bloke with a funny-looking doodad he calls a screwdriver, but this is true.