A Ahmad Indian Institute of Science, Bangalore A platform to understand the mechanism of life and existence beyond earth lies in extreme environments and their signatures. Bioproxies such as microbial mats and stromatolites play a vital role in understanding life's origin and behaviour throughout history. Both proxies represent the earliest sign of life with the probable common producers reported from the Archean Eon. Stromatolites are the world's oldest known signature of life recovered from Australia (Marble Bar in the Pilbara) around 3.45 billion years old. Whereas microbial mat (Microbially Induced Sedimentary Structures (MISS)) is another clear sign of life, found in around 3,480 million years old strata of Western Australia. Thus, the study of microbial diversity in the form of their size, shape, relief, and interaction with the environment is key to understanding to predict the earliest life. A modern hot water spring in Puga Valley, Ladakh, India (altitude 4414 meters; temperature 74oC; pH 7.4) shows conical-shaped microbial build-ups on the thick quilted base of the photo synthetic microbial mat. In a modern environment, microbial build-ups that are flat or pinnacle/conical-shaped are rare. There are very few modern-day environments, such as Lake Unterese, Joyce, and Vanda, Antarctica (Anderson et al., 2011; Haws et al., 2011, 2013), that have almost identical microorganisms growing, but in extremely cold water. Modern hot water springs and volcanic lakes have been reported to produce stromatolites with different morphologies (Jones et al., 2000; Farías et al., 2013; Berelsonet al., 2011). Conical / pinnacle structures are not fully understood how they form. Different microbial communities might have played a crucial role in forming a quilted base for pinnacle-shaped microbial growth. Studies of thermophilic cyanobacteria are also best conducted in the Ladakh region due to its hot springs. As demonstrated in the earlier experiment (Glucose uptake rate by thermophiles at Puga Hot Spring, Ansari et al., 2020), these extremophiles are not only able to survive above 70-80°C, but also regulate the photosynthesis process. As a result of the present study of quilted mats and conical/cuspate pinnacles microbial build up and different micro-organisms adapting to extreme environments, we gained a better understanding of how ancient Archean stromatolites and the earliest microbial ecosystems developed in extreme conditions.