We report the detection for the first time in space of three new pure hydrocarbon cycles in TMC-1: c -C 3 HCCH (ethynyl cyclopropenylidene), c -C 5 H 6 (cyclopentadiene), and c -C 9 H 8 (indene). We derive a column density of 3.1 × 10 11 cm −2 for the first cycle and similar values, in the range (1−2) × 10 13 cm −2 , for the second and third. This means that cyclopentadiene and indene, in spite of their large size, are exceptionally abundant, only a factor of five less abundant than the ubiquitous cyclic hydrocarbon c -C 3 H 2 . The high abundance found for these two hydrocarbon cycles together with the high abundance previously found for the propargyl radical (CH 2 CCH) and other hydrocarbons, such as vinyl and allenyl acetylene (Agúndez et al. 2021, A&A, 647, L10; Cernicharo et al. 2021a, A&A, 647, L2; Cernicharo et al. 2021b, A&A, 647, L3), start to allow us to quantify the abundant content of hydrocarbon rings in cold dark clouds and to identify the intermediate species that are probably behind the in situ bottom-up synthesis of aromatic cycles in these environments. While c -C 3 HCCH is most likely formed through the reaction between the radical CCH and c -C 3 H 2 , the high observed abundances of cyclopentadiene and indene are difficult to explain through currently proposed chemical mechanisms. Further studies are needed to identify how five- and six-membered rings are formed under the cold conditions of a cloud such as TMC-1.