The Manchester Bypass is the original all-weather route from beyond Eureka Junction back to County Pot, but it is also a worthwhile route in its own right, and makes a good alternative return from beyond Eureka Junction. It's also a lot easier to find your way through than its reputation would lead you to believe.
At Stop Pot, climb to the top of the boulder slope where you will find one of the few iron ladders remaining in the system. This leads into the High Level Route to Lancaster Hole. The route initially follows a rift passage, and involves clambering round, over, and under a series of greasy boulders, until you arrive at a low but impressive chamber called Main Line Terminus. Straight on heads towards Lancaster, and left heads into a well decorated passage to Carrot Chamber. Follow this passage for a few metres, until you see a gap in the right hand wall. This leads into Main Line Passage. To the right, another well decorated passage leads to a window overlooking Snail Cavern on the high level route; left leads towards the Manchester Bypass.
Follow the passage until there is a positive step up into a crawl. Follow this for a few metres, trending right, until you emerge out of a small hole in the floor of the rather uninspiring Old English Chamber. The way on is another small hole at floor level, which is best tackled head first. The route from here is pretty obvious, although a little arduous at times, and includes descents into two different chambers, both with fixed aids in place.
The end of the passage is marked by a 2 metre climb down, shortly after the second fixed aid descent. The quickest way back into County is up through some boulders to the left into Battle of Britain Hall, and out at the opposite end down into a boulder crawl. The way on leads immediately into the main County passages, a couple of metres upstream of Spout Hall.
The most direct route back to the surface is to turn left, but more fun is to turn right down Spout Passage and follow the stream down to Platypus Junction. Here Spout Passage combines with Razor Passage to become North West Passage, down which the stream flows. Turn left up Razor Passage, and follow the stream back to Broadway. Route finding through some breakdown chambers is a little challenging, but you can't go too far wrong. At one point, the impressive Butterfield Passage brings in most of the water from the right, with the entrance being marked by a prominent limestone pillar (The Toadstool). Ignore it and keep to the left passage.