LT2021 m. Biržuose, rekonstruojamos J. Janonio aikštės teritorijoje vyko tęstiniai tyrimai, pradėti 2019 m. (ATL 2019 metais, 2020, p. 216– 216), tęsti 2020 m. (V. Memgaudis) (ATL 2020 metais, 2021, p. 315–317). Šiais metais atlikti detalieji tyrimai, ištirtos 5 perkasos (99,2 m2 bendro ploto), vykdyti žvalgomieji tyrimai (56 m2 plote) ištiriant 3 perkasas ir 9 šurfus bei atlikti žvalgymai 7615 m2 bendrame plote. Archeologinių tyrimų metu J. Janonio aikštės R pusėje, važiuojamojoje dalyje, J. Basanavičiaus gatvės P pusėje (atkarpoje nuo J. Basanavičiaus g. 2 pastato iki tilto per Apaščios upę) po tarybiniu laikotarpiu įrengto asfalto danga atidengti natūralių lauko riedulių grindinio fragmentai, kurie pagal istorinius duomenis turėjo būti įrengti XIX a. pabaigoje – XX a. pradžioje. [...] [p. 283].
ENThe Biržai investigation begun in 2019 at J. Janonio Square, which is being renovated, continued in 2021 with the excavation of 8 trenches and 9 test pits (totalling 155.2 m2) and the survey of a total of 7615 m2. The investigation uncovered late 19th – early 20th-century fieldstone paving and paving fragments as well as, in the N part of the square, the top of the foundation from a first half of a 20th-century building. Trench 3 yielded an 18th-century building foundation with an apron fragment, Trench 4 a mid-17th-century fieldstone paving fragment with the corner of a nearby former wooden building (a semi- or full cellar?), Trench 5 a 1730s stove pad fragment and a second half of the 17th-century cultural layer containing sherds of household pottery and stove tiles characteristic for this period (Fig. 3), glass shards from windows, bottles, and dishes, and chopped up animal bones, Trench 6 a first half of the 17th-century storage pit containing sherds of household pottery characteristic for this period, several stove tile sherds, window glass shards, and chopped up animal bones, and Test Pit 15, at a depth of 2.55–2.65 m, the burial of a 30–39-year-old female without grave goods that dated to the 17th – second half of the 19th century.