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The compactified moduli space before blowups. The four divisors of closed string origin, depicted with a thicker line, include the large volume divisor $C_\infty$, the conifold locus $C_{\rm con}$, the enhanced symmetry locus $C_0=\{\psi=0\}$ and the locus $C_1=\{\phi^2=1\}$. The thinner line represents the open string discriminant $C_d$. Theorbifold point lies at the intersection of $C_0$ and $C_d$.

The moduli space blown up according to \cite{cdfkm} such that the closed string boundary divisor has normal crossings. The large volume point lies at the intersectionof $C_\infty=\{z_1=0\}$ with $D_{(0,-1)}=\{z_2=0\}$, and is also met by $C_d$.

Close up of large volume point, with additional blowup depicted on the right. The coordinate on the exceptional divisor $D_d$ is denoted $y^3=1/x^3\sim\frac{z_1}{z_2}$in the text.

Close up of large volume point, with additional blowup depicted on the right. The coordinate on the exceptional divisor $D_d$ is denoted $y^3=1/x^3\sim\frac{z_1}{z_2}$in the text.