Meditation is an activity in which the practitioner just sits and allows the mind to dissolve. In Art of Living, meditation is a simplified activity which can easily be practiced by all. Meditation is not concentration. It is de-concentration.
The rest in meditation is deeper than the deepest sleep that you can ever have. When the mind becomes free from agitation, is calm and serene and at peace, meditation happens.
You can perform meditation in any calm place. However, the best ashrams to find your inner peace would be Patanjali International Yoga Foundation and Anand Prakash Ashram.