Wide-area surveys of the Galactic halo reveal the so-called “Field of Streams” toward constellations such as Hercules and Aquila, where multiple overlapping stellar streams, clouds, and overdensities (including parts of the Sagittarius stream, the Orphan stream, and the Hercules–Aquila cloud) crisscross the same region of sky with different distances and kinematics (Belokurov et al. 2006; Belokurov et al. 2007). In ΛCDM, the stellar halo is expected to be built largely from disrupted satellites, but reproducing such a rich, overlapping network of long, cold, spatially correlated streams in a limited sky area—while still matching the global halo density profile and dark-matter halo shape—requires carefully tuned accretion histories and subhalo properties, making this “Aquila field of streams” a nontrivial constraint on standard models of halo formation (Johnston et al. 2008; Helmi 2020).