There are several small tubes leading off both right and left near the start of Dartford Tunnel [C1982-41-00], also downhill, but none of these crawls/stoops have been pushed to a conclusion. There may also be high leads to the left 40m [C1982-41-01] and 60m [C1982-41-02] from the start.
Where Dartford Tunnel turns abruptly right (NW) and changes into a high rift, there is a possiblity of a passage to the left, about 6m up the wall, continuing the line of the rift in the opposite direction [C1982-41-04] to the SE. This NW-SE joint is parallel with the Big Rift of Stellerweg, and seems to be a major influence in this area.
The joint-guided rift ends abruptly at a T-junction where the main way is left in SW-trending vadose canyon. To the right is also big passage, leading Northeast to an aven with an inlet [C1982-41-05], but no way on. On the main way, at a 4m climb down, a passage comes in from the right, also NE; this may be followed to a low area of mud and boulders [C1982-41-06] with no continuation.
Where the Purgatory Bypass finally intersects the canyon of the stream entering at the Confluence, the main way is to the left on a ledge. No attempt has apparently been made to follow the canyon to the right at high level [C1982-41-12], perhaps because of its angle and lack of friction.
The main way crosses the canyon to a terrace, and drops down from here to the Confluence from a corner. If, instead of dropping down here, the terrace is followed round the corner to the right, it leads to a dry vadose trench in the floor and then a traverse above the main streamway. Rampant Passage starts near this corner and rises as a large dry passage, 7m high and 2m wide. This climbs 30m in its 65m length to emerge at a huge chamber, Cologne Cathedral (Köln Dom) approximately 15m in diameter and apparently 20m high. A dangerous climb, c10, c5m leads to 25m of passage ending in the huge 30m high Echo Aven [C1982-41-14]. It's not entirely clear whether there is a way on [C1982-41-13] in the roof of Köln Dom.
Many of the passages in these levels contain dead bats, perhaps suggesting a lower entrance, though this seems unlikely to be nearby. Some of the deeper passages of Schwabenschacht (1623/78) are near this area, perhaps 200m above the Confluence. The top of Echo Aven is near to halfway to bridging this gap, which suggests the possibility of a connection in the next few years.
The climb down from the Bypass lands at the junction of the Purgatory water and an inlet [C1981-41-07] which can be followed upstream (ESE) in a passage similar to the Purgatory, until soon after a 7m climb up, the streamway divides twice and becomes too small to follow. This is thought to be the Stellerweg water, last seen in Junction Chamber, but is likely also to include water from various inlets and floor trenches seen in Dartford Tunnel, as there are no inlets in the Purgatory itself.
Downstream of the Confluence, just after the first (4m) wet climb is the entry of a dry inlet on the right, which leads back towards the Confluence, but was not pushed to a conclusion [C1982-41-15]. Shortly downstream, below the 7m pitch, the streamway feeding the cascade on the left [C1982-41-16] remains unexplored (this is shown on the right on the survey, not the left).
Where the sump bypass drops back to the main stream, the continuing way up is unexplored [C1981-41-22]. Halfway between the next 3m pitch and the Twelve Foot Climb, (50m from each) another inlet enters from high up, this time on the right [C1981-41-23]. Much further on, another unexplored inlet up on the left [C1981-41-24], shortly precedes the Subtle Approach Pitch.