We present CaII and NaI spectra for a sample of stars in a 30'×30' field connecting 30 Dor with SN 1987A. Observations were taken with the CES spectrograph linked via fibres with the 3.6m ESO telescope at a resolution of ˜ 6 km s−1. The LMC gas shows a complex structure with both single and multiple components spanning 250 to 300 km s−1. Results can be interpreted using the multi-layer structure suggested by 21 cm observations. Comparing our optical absorptions with 21 cm emissions yields evidence that layers with increasing radial velocity are located one behind the other. The intermediate velocity components are numerous in CaII, but rare in NaI. Towards Sk-69 211, for which we have the highest S/N CaII spectrum, we have detected a number of components comparable to that found in SN 1987A. The 64 km s−1 cloud is detected in a well-confined region of the field, showing remarkable constancy in the radial velocity, which we interpret as evidence that this cloud is located close to the Galaxy.