The field of nanomechanics explores mechanical motion at the nanoscale. This motion can be torsion or bending of thin beams or membranes, surface acoustic waves traveling along surfaces, bulk acoustic modes in the volume of a material or engineered resonances in acoustic metamaterials. Shrinking the device dimensions to the nanoscale allows for frequencies up to the mid-GHz range and quality factors exceeding 10 billion. Nanomechanical resonators in the GHz range are promising candidates for quantum memory and quantum coherent microwave-to-optical transduction schemes. Additionally, the high achievable quality factors turn them into sensitive spectroscopy tools: Carefully characterizing geometry, eigenfrequencies and damping of a nanomechanical resonator allows to infer material parameters such as strain or Young's modulus, which is often difficult to probe by other means in epitaxial thin films or exfoliated samples. Also, virtually any property of a solid (or its surface or defects) is strain-dependent, therefore nanomechanical resonances couple to magnetic and optical degrees of freedom of most materials opening countless opportunities for transduction and sensing. I will give an overview of experimental work done in our group highlighting our recent efforts towards interfaces between mechanical modes, single photon emitters, spin-resonances in SiC, h-BN and MoS2 nanomechanical resonators.