LT2009 m. buvo tęsiami 2007 m. pradėti Vilniaus bastėjos archeologiniai tyrimai (žr. ATL 2007 metais, V., 2008, p. 219–226; ATL 2008 metais, V., 2009, p. 201). Vykdant restauracijos darbus, planuota sutvirtinti pamatų išorinę dalį. Tam reikėjo visu išoriniu (R) pasagos perimetru iškasti apie 1 m pločio ir apie 1 m gylio tranšėją. Bendras plotas sudarė apie 120 m2 [p. 162].
ENIn 2009, the investigation, begun in 2007, of the Vilnius bastion was continued. In planning to reinforce the external part of the foundations, a 1 meter wide and about 1 m deep trench (5 test pits and 11 segments with a total area of about 120 m2) was dug around the entire outside perimeter of the (E) horseshoe. It was determined that a greater part of the bastion’s foundations were built on stable clay or gravel layers. In one test pit and 4 segments a fill layer of black peaty earth, placed there during the period of the bastion’s existence, was discovered. In the undisturbed part of the layer were found tens of late 16th – early 17th-century pottery sherds, animal bones, small stove tile fragments, and a 1.75 x 2.8 cm, 3.46 g gold pendant. The top of the base element of the bastion’s horseshoe foundation was fixed at about Habs 120.50 m and the foundation’s bottom at Habs 119.30–119.60 m. The NE part of the foundation was almost even with the ground surface. The ground surface at the horseshoe’s exterior was at Habs 120.35–119.70 m.