A visit to New Vrindaban Dham, USA (Album with photos)
Srila Prabhupada: Krishna’s Lila in Vrndavana is prakata or manifest Lila, and the same is going on eternally in the spiritual realm, which is known as aprakata or nonmanifest. Krishna’s planet and Krishna’s pastimes are going on eternally, and the same is manifested before the conditioned souls at certain intervals, once in one day of Brahma, exactly as the sun is visible for 12 hours once a 24 hour cycle of and night. When the sun is visible it is called prakata, and when the sun is not visible that is called aprakata or unmanifested. Non-manifested therefore does not mean there is no existence, but the terms are used in relation to the visibility or non-visibility to the limited conditioned souls. Letter to Shyamasundara, May 14, 1970.
Find them here: https://goo.gl/ZhrIhf