The
Alay or
Alai Mountains (; ) constitute a mountain range that extends from the
Tien Shan mountain range in
Kyrgyzstan west into
Tajikistan. It is part of the
Pamir-Alai mountain system. The range runs approximately east to west. Its highest summit is
Pik Tandykul , 5544 m. The southern slopes of the range drain into the
Vakhsh River, a tributary of the
Amu Darya. The streams that drain the northern slopes of the range are tributaries of the
Syr Darya, and empty into the
Fergana Valley to the north of the range.