Burned grasses found in an Australian cave may reveal ritual traditions dating back 25,000 years. These findings, based on microscopic plant remains known as phytoliths, suggest that the GunaiKurnai ancestors used Cloggs Cave for spiritual practices over thousands of years. The evidence includes layers of ash and a standing stone, which support the idea that the cave was a long-standing spiritual site. The GunaiKurnai are the traditional custodians of Gippsland and the southern Victorian Alps, and their oral histories and 19th-century accounts describe caves as places for rituals involving magic, healing, and other spiritual practices. Researchers examined phytoliths—microscopic silica structures that form in plant tissues and can survive long after the plant has decayed—from buried sediments inside Cloggs Cave. This research, conducted in 2019 and 2020, was initiated by the GunaiKurnai Land and Waters Corporation, with GunaiKurnai representatives involved in every stage of the study. Phytoliths differ from pollen, which is spread by wind or insects, as they mostly accumulate at the location where the plant decays. Since no plants grow inside the cave due to the lack of light, the phytoliths must have been brought in by people or animals. The researchers focused on half-burnt phytoliths found in ashy layers, which could only have been introduced by humans. These findings suggest that people intentionally carried whole grasses into the cave and burned them, leaving behind traces that may span 25,000 years. Layers of ash and a standing stone, placed around 2,000 years ago, further support the idea of long-term ritual use. The phytoliths included 29 different types of grasses, herbs, and woody plants, with grass phytoliths making up as much as 97% of the total. These grasses were carefully selected, even though the surrounding landscape had a variety of plant species. The study found that up to 18% of the phytoliths showed signs of burning or melting, indicating repeated ritual burning over thousands of years. These findings align with other evidence suggesting that Cloggs Cave was a site of enduring spiritual activity rather than a typical living space. Professor Bruno David from Monash University, who co-led the research, notes that the use of ash in rituals aligns with GunaiKurnai traditions, including tracking the footsteps of people and spirit-beings. Additional evidence, such as fat-smeared, trimmed wooden sticks from Casuarina trees, suggests that other types of rituals involving woody plants were also performed in the cave.