Structure of the dark matter (DM) and gaseous cosmic web at z = 0 in EAGLE (top row) and TNG100 (bottom row). All six panels show a field of view of 50 × 50 Mpc, with a projection depth of 5 Mpc. DM density is shown in the left-hand panels, gas density in the middle, and mass-weighted gas temperature on the right. While the DM structures are near-indistinguishable, there are clear differences between the simulations in both gas density and temperature, as discussed in the text. Particularly noteworthy is the prominence of small gas-rich haloes in TNG that are absent in EAGLE, and the ubiquity of warm gas around filaments in EAGLE.