Employing sub-wavelength meta-molecules, unnaturally extreme optical properties can be realized due to their strong resonant response. However, highly dispersive optical proper-ties in resonant type metamaterials has been obstruction for broad-bandwidth operation as effective meta-devices. Broadband capabilities of metamaterials will allow dramatic oppor-tunities in designing myriad of novel optical systems and applications. Here we propose two types of chiral metamaterials to achieve extremely strong and broadband chirality through 3D chiral metamaterials. Utilizing conjugated double Z chiral metamaterials, we show that extremely gigantic chirality can be achieved by their strong inter-molecular interactions. And we demonstrate theoretically and affirm experimentally that broadband, dispersionless and strong optical activity can be realized in meshed spiral metamaterials where metallic spiral structures are networked and arranged with four-fold rotational symmetry. This non-resonant behaviour comes from the specifically designed dispersion of chirality parameter