Low dimensional magnetism provides a crucial playground for the discovery and exploitation of unconventional magnetic properties. With in this context the study of 1D magnetic systems is arguably the topic of strongest scientific interest. The experimental realisation of some of the key theoretical models is still a fundamental challenge and the area where this experiment will make a contribution. Coordination frameworks, including dense metal-organic frameworks (MOF's) are natural platforms in which to study low dimensional magnetism because they tend to form very anisotropic structures. In this experiment we propose to investigate the properties of one of these systems, Tb(HCO2)3, using muSR. This material realises the model for triangular Ising antiferromagnet for the first time. We would like to investigate the properties of this phase as a function of temperature and magnetic field.