For every coin, there are multiple URLs you can connect your mining device to. Slush Pool servers are located all around the world. For better connection and lower latency, please use one of the location-specific URLs instead of the general URL.
When configuring the miner, just choose the URL according to your geographical location (or the nearest one) and set it up in the mining device settings. You can find the list of our servers in Help Center for the coin you would like to mine with us.