Abstract: Geophysical fluid dynamics is a discipline that investigates the macroscopic motion laws of fluids in nature, with broad applications in climate research and related fields. Rotating tanks play a crucial role in simulating natural fluid motions by employing scaling principles and topographic modeling to reproduce multiscale physical processes of stratified fluids under rotating conditions, and capturing fundamental features of oceanic and atmospheric environments. This paper focuses on the design principles and system composition of the large-scale rotating tank constructed at the international geophysical fluid dynamics laboratory (iGFDL), Nanjing University of Information Science and Technology. With an inner diameter of 14 m and an outer diameter of 18 m, it is the second rotating tank globally to exceed an inner diameter of 10 m. The system comprises four main components: the large tank body, a multi-density water exchange system, an observation system, and multivariate analysis system. Notably, the observation system incorporates an automated lifting device and employs state-of-the-art optical altimetry technology, features unprecedented in previous large-scale rotating platforms. Additionally, this paper presents mesoscale vortex experiments conducted on other rotating platforms, including studies on vortex evolution and vortex-vortex interactions, as well as experiments exploring the classification and stability of estuarine plumes. The results show that: (1) Centrifugal instability leads to a slow decay phase of vortices, while vortex-vortex interactions induce rapid decay, both being key factors in the dissipation of anticyclonic vortices; (2) During vortex merging, vorticity diffuses outward, accumulating vortex filaments and generating asymmetric vorticity, which affects merging efficiency—convective processes driven by asymmetric vorticity constitute one mechanism of vortex merging; (3) Shelf slope has minimal influence on the maximum depth of estuarine plumes but significantly affects their width. This large rotating tank platform aims to serve researchers worldwide, foster in-depth collaboration between domestic and international institutions, and advance the future development of geophysical fluid dynamics research.