S3 E2 The "Dan Tian" (丹田): its physical aspect
The Taichi and Qigong Podcast - A podcast by The Taichi and Qigong Podcast

Nobody has ever been able to approach any Chinese energetic art (say Taichi or Qigong) without encountering the concept of "Dan Tian" (丹田), or "Elixir Field". We will see how the Elixir was intended to give immortality (in lieu of the awakening in the buddhist theories), of the shape, size and location of the Dan Tian widely varies in different centuries or schools, and how it is related to the physical nature of Homo Sapiens.