The advancement of limnology and lake science has compellingly demonstrated the critical importance of long-term field observations and experimental research. Globally, scientific institutions have established long-term field observation stations—such as those at Lake Flathead, Lake Trout, USA, and Lake Zurich, Switzerland—to systematically conduct research spanning decades to over a century on the evolution, impact mechanisms, and sustainable management of lake ecosystems. Supported by the Chinese Ecosystem Research Network and the National Science and Technology Infrastructure Platform Center, Chinese scientists have successively constructed field observation and experimental stations at sites including East Lake (Wuhan), Lake Taihu, Lake Poyang, Lake Dongting, and Lake Liangzi, undertaking long-term experimental monitoring and networked comprehensive studies of lake ecosystems. This study systematically reviews the progress of long-term, site-specific observation and experimental research in lake science, both globally and within China. Through cross-national, cross-regional, and cross-lake-type case comparisons, it highlights the irreplaceable role of such sustained, location-based observations in uncovering the dynamics of lake ecosystems. The study emphasizes that only through cross-regional networked observations, enhanced informatization and intelligence in monitoring, and the integration of observational data with simulation models can we deeply analyze the response processes and resilience mechanisms of lake ecosystems to climate change and human disturbances. This synthesis provides crucial scientific support for global lake conservation, ecological restoration, and sustainable utilization, thereby propelling lake science forward from "phenomenon description" to "mechanism analysis" and "predictive early-warning". Ultimately, this work serves the objectives of the United Nations Sustainable Development Agenda and the Beautiful China Initiative.