This dataset contains the position and depth (ice thickness) of three spatially-extensive Internal Reflecting Horizons (IRHs) mapped from ice-penetrating radar data acquired with the British Antarctic Survey's PASIN and PASIN2 ice radar systems across central East Antarctica. The dataset extends geographically from Dome A to South Pole. Using previous dated IRHs from Winter et al (2019), an independent validation of IRH ages from the South Pole ice-core chronology and a 1-D steady-state model, we assigned ages to our three IRHs: (H1) 38.5 +/- 2.2 ka, (H2) 90.4 +/- 3.57, and (H3) 161.9 +/- 6.76 ka. This study was motivated by the AntArchitecture Action Group of the Scientific Committee for Antarctic Research (SCAR). The project was supported by the National Environmental Research Council (NERC)-funded ONE Planet Doctoral Training Partnership (NE/S007512/1), hosted jointly by Newcastle and Northumbria Universities. The authors thank the BAS science and logistics teams for acquiring both the AGAP PASIN and PolarGAP PASIN2 data which is fully available on the Polar Airborne Geophysics Data Portal of the UK Polar Data Center (https://www.bas.ac.uk/project/nagdp/). BedMachine (version 2) data are available at https://doi.org/10.5067/E1QL9HFQ7A8M.

The dataset consists of 14 selected lines of radar data, collected from the Little Dome C region close to Concordia Station in East Antarctica. The data were collected in austral field seasons 2016-17, and 2017-18, from within the search region for the planned European project Beyond EPICA - Oldest Ice, an EU-funded 10-nation consortium project to drill an ice core that spans up to 1.5 million years of climate and atmospheric history. Radar lines were recorded using the BAS DELORES sledge-borne, over-snow, ice radar system and geolocated with a precise GPS system. This data was generated within the project Beyond EPICA - Oldest Ice (BE-OI). The project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 730258 (BE-OI CSA). It has received funding from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number 16.0144. It is further supported by national partners and funding agencies in Belgium, Denmark, France, Germany, Italy, Norway, Sweden, Switzerland, the Netherlands and the UK. Logistic support is mainly provided by AWI, BAS, ENEA and IPEV. Collection of this data also benefited from support by the joint French-Italian Concordia Programme, which established and runs the permanent station Concordia at Dome C. We particularly acknowledge those who collected the data in the field, and assisted with the processing: Robert Mulvaney, Massimo Frezzotti, Marie Cavitte, Ed King, Carlos Martin, Catherine Ritz, Julius Rix.