Mottingham 4 August 1585: The cause of the incident, referred to as a "marvellous accident" at the time, was then unknown, and it is likely that a sinkhole had developed. The area is well coursed with streams, both above and below ground, and the collapse or shifting of subsoil might be attributed to them. The site of the sinkhole is now unknown, and the incident is also largely unknown. The only body of standing water that is in the area today is a lake at The Tarn Bird Sanctuary. In the NW corner of The Tarn opposite Mottingham Station is an
Danube Sinkhole other hand, to decide the smoldering controversy over the quantitative impact of the Danube sinkhole, which is known as the Danube Sinkhole case (). As the karst is developing, future sinkhole stretches cannot be accurately predicted. The underground river Danube annually removes about 7,000 tons of lime, that is 2,700 cubic meters, from the karst system. Future expansions or collapses in the underground system are conceivable, which would show above ground as sinkholes or ponors. In the long run, today's upper Danube will probably be redirected entirely into the Radolfzeller Aach, and thus to the Rhine. This would mean that